<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>默认this绑定</title>
    <script>
        //绑定全局对象
        var a=1;
        function f(){
            var a=2;
            g();
            function g(){
                console.log(this.a);
            }
            return g;
        }

        f()();
    </script>
</head>
<body>
    
</body>
</html>